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Article
Publication date: 24 August 2018

Long Meng, Meng Liu, Lingjiu Zhou, Wanpeng Wang, Cuilin Liao, Lice Zhao and Tieyou Li

Cavitation inside pumps affects not only the steady state fluid flow, but also the unsteady or transient characteristic of the flow. However, cavitation inside pumps under…

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Abstract

Purpose

Cavitation inside pumps affects not only the steady state fluid flow, but also the unsteady or transient characteristic of the flow. However, cavitation inside pumps under transient processes is difficult to predict when the influence of the pipelines system is considered. In this paper we present a simulation method applied to a centrifugal pump and its related pipeline to analyze the induced unsteady cavitation phenomenon during the startup process.

Design/methodology/approach

In order to effectively predict transient processes of a pump and its pipeline system, the simulation method uses a coupled 1D and 3D scheme, which reduces the simulation cost. The simulation of the startup process of a centrifugal pump in a closed-loop pipeline system with and without cavitation has been performed to verify the proposed method.

Findings

The evolution of the pressure and flow rate obtained with the simulation method agrees well with the experimental results. It is found that the mass flow rate at the pump inlet and outlet is highly related to the cavitation vapor volume and that the pressure at the outlet of the impeller is greatly influenced by the discharge.

Originality/value

The 1D-3D coupling simulation method used in this paper is proven to be highly accurate, efficient and can be used to solve transient processes combined with cavitation or other complex phenomena.

Details

Engineering Computations, vol. 35 no. 5
Type: Research Article
ISSN: 0264-4401

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Article
Publication date: 5 February 2018

Meng-Long Huo and Peter Boxall

Grounded in the theory of person-organisation fit, the purpose of this paper is to investigate the extent to which instrumental work values influence the relationship between HR…

1607

Abstract

Purpose

Grounded in the theory of person-organisation fit, the purpose of this paper is to investigate the extent to which instrumental work values influence the relationship between HR practices and employee well-being (measured by job satisfaction) in a sample of Chinese workers.

Design/methodology/approach

Questionnaire data for this cross-sectional, quantitative study were collected from 371 front-line workers in a Chinese manufacturer. Structural equation modelling was used to test the hypotheses.

Findings

The results show that work instrumentalism significantly reduces the positive effect of training on job satisfaction while boosting the positive effect of remuneration on job satisfaction. In contrast, there is no evidence for an interaction between instrumentalism and employee involvement.

Practical implications

The results imply that the degree to which HR practices are effective in promoting job satisfaction among these Chinese workers depends both on their work-value orientations and on the implications of the particular HR practice. Managers concerned about job satisfaction in China need to consider the impact of work values and the goals of particular HR practices.

Originality/value

China makes an enormously important contribution to world manufacturing output but the authors need a better understanding of how Chinese workers are likely to interpret and respond to HR practices if employee well-being in Chinese enterprises is to be fostered.

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Article
Publication date: 17 October 2024

Meng-Long Huo

Underpinned by the exit-voice and work design models, this study investigates how work autonomy reduces employee turnover intentions and promotes voice behavior via the mediator…

102

Abstract

Purpose

Underpinned by the exit-voice and work design models, this study investigates how work autonomy reduces employee turnover intentions and promotes voice behavior via the mediator of skill utilization and how this mediation process is moderated by social (learning from colleagues) and personality (future time orientation) characteristics.

Design/methodology/approach

The hypothesized moderated mediation model was tested using regression analysis based on two-wave survey data of 350 Chinese employees.

Findings

The relationships between work autonomy on the one hand and voice behavior and turnover intentions on the other were mediated by skill utilization. Furthermore, such mediated relationships were intensified by collegial learning and future time orientation.

Practical implications

Adopting empowering HR practices (e.g. autonomous work teams and job rotation) that give employees job control and learning opportunities is important to encourage employee voice and reduce turnover.

Originality/value

The paper identifies collegial learning and future time orientation as boundary conditions that regulate the effects of work autonomy. This reconciles the contradictory findings in prior research testing the relationship between autonomy and exit-voice decisions.

Details

Personnel Review, vol. 54 no. 1
Type: Research Article
ISSN: 0048-3486

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Article
Publication date: 10 February 2022

Meng-Long Huo, Zhou Jiang, Zhiming Cheng and Adrian Wilkinson

Grounded in the job demands–resources (JD-R) theory, this study investigates how the difficulty in social distancing at work, resulting from the COVID-19 crisis, may lead to…

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Abstract

Purpose

Grounded in the job demands–resources (JD-R) theory, this study investigates how the difficulty in social distancing at work, resulting from the COVID-19 crisis, may lead to intention to quit and career regret and how and when these effects may be attenuated.

Design/methodology/approach

Three-wave survey data were collected from 223 frontline service workers in a large restaurant company during the COVID-19 crisis.

Findings

The results show that difficulty in social distancing reduced employees' work engagement, and consequently, increased their turnover intention and career regret. These relationships were moderated by external employability, such that the influence of difficulty in social distancing weakened as external employability increased.

Originality/value

Social distancing measures have been applied across the globe to minimize transmission of COVID-19. However, such measures create a new job demand for service workers who find it difficult to practice social distancing due to the high contact intensity of service delivery. This study identified personal resources that help service workers cope with the demand triggered by COVID-19.

Details

Journal of Service Theory and Practice, vol. 32 no. 2
Type: Research Article
ISSN: 2055-6225

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Article
Publication date: 9 July 2021

Phuoc Luong Le and Nguyen Thi Duc Nguyen

To deal with the present situation and recover after the COVID-19 pandemic, construction firms are required to recognise the trends in construction supply chain management (CSCM…

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Abstract

Purpose

To deal with the present situation and recover after the COVID-19 pandemic, construction firms are required to recognise the trends in construction supply chain management (CSCM) for the upcoming years and determine the appropriate practices towards the trends for the improvement of construction activities in terms of strategy, tactic and operations. This paper aims to recognise key trends in CSCM and uses these trends as strategic criteria for the evaluation and prioritisation of lean construction (LC) tools at different project phases including design and architectural engineering, planning and control, on-site construction and safety management.

Design/methodology/approach

The integrated analytic hierarchy process–Delphi method is used to collect and analyse the data from construction experts to evaluate the importance levels of the CSCM trends and recommend the appropriate tools for LC practices to improve project performances.

Findings

Seven key CSCM trends are identified: lean supply chain management (SCM), supply chain (SC) integration, SC standardisation, SC problem-solving, SC information-sharing, SC flexibility and SC sustainability. Based on these trends, a set of prioritised lean tools are suggested for LC practices, in which “virtual design construction” (VDC) and “last planner system” are considered as the central tools. These two LC practices can be integrated with other effective tools to support the strategic, tactical and operational targets in construction supply chain (CSC) projects.

Research limitations/implications

This study gives the managerial implications by developing an application framework of LC practices for CSC projects. The framework promotes “VDC” as a strategic tool for the phase of design and architectural engineering and considers “last planner system” as the central LC practice for the phase of project planning and control. The framework also focuses on the improvement of efficiency in construction operations by taking into account the aspects of on-site collaboration, problem-solving, improvement and safety.

Originality/value

Up to date, there is still a lack of researches in classifying and prioritising the significant LC tools for each project phase to deal with CSC issues in both breadth and depth. Thus, this study is performed to provide construction managers with the awareness of CSCM trends on which they can focus to have strategic criteria for selecting LC practices to improve CSC performances.

Details

International Journal of Lean Six Sigma, vol. 13 no. 3
Type: Research Article
ISSN: 2040-4166

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Article
Publication date: 6 July 2022

Theodoros Daglis

The COVID-19 pandemic is known to have affected the logistics and supply chains; however, there is no adequate empirical evidence to prove in which way it has affected the…

229

Abstract

Purpose

The COVID-19 pandemic is known to have affected the logistics and supply chains; however, there is no adequate empirical evidence to prove in which way it has affected the relationship between the stocks related to this field with the corresponding cryptocurrencies. This paper aims to test the dynamic relationship of cryptocurrencies with supply chain and logistics stocks.

Design/methodology/approach

In this paper, the author tests the causal and long-run relationship between logistics and supply chain stocks with the corresponding cryptocurrencies related to these fields, or those that are known to exhibit characteristics that can be utilized by these fields, testing also whether the COVID-19 pandemic affected this relationship. To do so, the author performs the variable-lag causality to test the causal relationship, and examines if this relationship changed due to COVID-19. The author then implements the multifractal detrended cross-correlation analysis to investigate the characteristics of a possible long-run relationship, testing also whether they changed due to COVID-19.

Findings

The results indicate that there is a positive long-run relationship between each logistics and supply chain stocks and the corresponding cryptocurrencies, before and also during COVID-19, but during COVID-19 this relationship becomes weaker, in most cases. Moreover, before COVID-19, the majority of the cases indicate a causal direction from cryptocurrencies to the stocks, while during COVID-19, the causal relationships decrease in multitude, and most cases unveil a causal direction from the stocks to cryptocurrencies.

Originality/value

The causal pattern changed during COVID-19, and the long-run relationship became weaker, showing a change in the dynamics in the relationship between logistics and supply chain stocks with cryptocurrencies.

Details

Journal of Economic Studies, vol. 50 no. 4
Type: Research Article
ISSN: 0144-3585

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Book part
Publication date: 15 July 2019

Peter Boxall, Meng-Long Huo, Keith Macky and Jonathan Winterton

High-involvement work processes (HIWPs) are associated with high levels of employee influence over the work process, such as high levels of control over how to handle individual…

Abstract

High-involvement work processes (HIWPs) are associated with high levels of employee influence over the work process, such as high levels of control over how to handle individual job tasks or a high level of involvement at team or workplace level in designing work procedures. When implementations of HIWPs are accompanied by companion investments in human capital – for example, in better information and training, higher pay and stronger employee voice – it is appropriate to talk not only of HIWPs but of “high-involvement work systems” (HIWSs). This chapter reviews the theory and practice of HIWPs and HIWSs. Across a range of academic perspectives and societies, it has regularly been argued that steps to enhance employee involvement in decision-making create better opportunities to perform, better utilization of skill and human potential, and better employee motivation, leading, in turn, to various improvements in organizational and employee outcomes.

However, there are also costs to increased employee involvement and the authors review the important economic and sociopolitical contingencies that help to explain the incidence or distribution of HIWPs and HIWSs. The authors also review the research on the outcomes of higher employee involvement for firms and workers, discuss the quality of the research methods used, and consider the tensions with which the model is associated. This chapter concludes with an outline of the research agenda, envisaging an ongoing role for both quantitative and qualitative studies. Without ignoring the difficulties involved, the authors argue, from the societal perspective, that the high-involvement pathway should be considered one of the most important vectors available to improve the quality of work and employee well-being.

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Article
Publication date: 16 January 2009

Yih‐Lin Cheng and MengLong Lee

In order to manufacture scaffolds for tissue engineering, a dynamic mask rapid prototyping system to cure UV‐curable biodegradable material was developed. The aim of this paper is…

1492

Abstract

Purpose

In order to manufacture scaffolds for tissue engineering, a dynamic mask rapid prototyping system to cure UV‐curable biodegradable material was developed. The aim of this paper is to document this system.

Design/methodology/approach

A digital micro‐mirror device (DMD) was used as the dynamic mask generator, with each layer's mask pattern dictated by our self‐developed software. To build the scaffolds, UV light reflected by the DMD was then focused onto the biodegradable material to cure it. The biodegradable material used in this experiment was a mixture of 85/15 PLGA, PEG‐HEMA, and a photo‐initiator.

Findings

The dynamic mask rapid prototyping system was successfully built and scaffolds made of UV‐curable biodegradable material were fabricated to verify the system capacity. The working exposure time for each layer was 45 s except for the first layer, which was 60 s. Scaffolds with 0°/90° and 60°/120° strips in alternating layers were fabricated and the pore size error in X and Y axes of 0°/90° design was found to be 7.33 and 2.13 percent, respectively. Preliminary cell culture tests indicate the fabricated scaffold is not harmful to MG‐63 cell growth.

Research limitations/implications

Different scaffold designs and more UV‐curable biodegradable materials may be further implemented and tested through this system.

Originality/value

This research developed a novel system for tissue engineering scaffold fabrication which can process UV‐curable biodegradable material.

Details

Rapid Prototyping Journal, vol. 15 no. 1
Type: Research Article
ISSN: 1355-2546

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Article
Publication date: 29 March 2013

Jing Yang, Long Meng, Lingjiu Zhou, Yongyao Luo and Zhengwei Wang

Thermal power plants have many problems regarding noise and vibration. Previous studies have shown that such problems are often related to the fans. However, the internal flows…

432

Abstract

Purpose

Thermal power plants have many problems regarding noise and vibration. Previous studies have shown that such problems are often related to the fans. However, the internal flows are difficult to analyze to find the cause of vibration and noise in fans in actual tests. Therefore, the unsteady internal flow field in a centrifugal fan was simulated numerical to identify the source. This paper aims to present these issues.

Design/methodology/approach

The unsteady Reynolds‐averaged Navier‐Stokes equations with the SST k‐ω turbulence model were solved to simulate the flow within the entire flow path of the fan. The conservation of mass and moment and energy equations were used to solve the flow field distribution. The time‐dependent pressure pulsations on the impeller were analyzed for the dynamics problem. The finite volume method with the SIMPLEC algorithm was used to discretize the time‐dependent equations. The second‐order upwind scheme was used for the convection terms and the central difference scheme was chosen for the diffusion terms in the momentum and transport equations.

Findings

The numerical simulations illustrated the flow characteristics inside the double suction centrifugal fan. The predicted efficiency is almost the same as the experimental value. The estimated pressure and temperature fields are quite reasonable. The results showed that the interaction between the non‐uniform impeller flow and the fixed volute aroused the significant pressure fluctuations, which is an important source of vibration and noise in centrifugal machinery.

Research limitations/implications

It is assumed that there is no change in the density in the whole flow passage, and the predicted outlet temperature is about 1.15 per cent lower than the experimental result.

Originality/value

The simulation study indicates that the prediction of noise is possible by using pressure pulsation. It is recommended to control the pressure pulsation in the fans, to decrease the vibration and noise of thermal power plants.

Details

Engineering Computations, vol. 30 no. 3
Type: Research Article
ISSN: 0264-4401

Keywords

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Book part
Publication date: 13 September 2018

Wenchao Ma, Lina He, Zeng Dan, Guanyi Chen and Xuebin Lu

With the rapid development of China’s urbanisation and market economy, municipal solid waste (MSW) generation is increasing dramatically. In response to the threat of…

Abstract

With the rapid development of China’s urbanisation and market economy, municipal solid waste (MSW) generation is increasing dramatically. In response to the threat of environmental pollution and the potential value of converting waste into energy, both the government and the public are now paying more attention to MSW treatment and disposal methods. In 2014, 178.6 million tonnes of MSW was collected at a safe treatment rate of 84.8%. However, the treatment methods and the composition of MSW are influenced by the collection area, its gross domestic product, population, rainfall and living conditions. This chapter analysed the MSW composition properties of Lhasa, Tibet, compared with other cities, such as Beijing, Guangzhou and so forth. The research showed that the moisture content of MSW in Lhasa approaches 31%, which is much lower than the other cities mentioned previously. The proportion of paper and plastics (rubbers) collected was 25.67% and 19.1%, respectively. This was 1.00–3.17 times and 0.75–2.44 times more than those found in Beijing and Guangzhou, respectively. Non-combustibles can reach up to 22.5%, which was 4.03–9.11 times that of Beijing and Guangzhou, respectively. The net heating values could reach up to 6,616 kilojoule/kilogram. The food residue was only half the proportion found in other cities. Moreover, the disposal method applied in each city has also been studied and compared.

Details

Unmaking Waste in Production and Consumption: Towards the Circular Economy
Type: Book
ISBN: 978-1-78714-620-4

Keywords

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